Do exercise for 4 weeks using rubber to increase the speed of gyaku tsuki karate punches gokasi karate athletes aged 16-20 years? . SPORTIF [Internet]. 2024 Dec. 23 [cited 2025 Mar. 10];10(3):390-404. Available from: https://ojs.unpkediri.ac.id/index.php/pjk/article/view/23115